ARINC 659 backplane data bus is a fault tolerant cabinet backplane bus with high level reliability.It is a key component of the integrated modular avionics as defined in ARINC Report 651.The requirements of the integrated modular avionics to the backplane data bus are presented.The ARINC Specification 659 is expatiated including the system architecture the media access protocol synchronization and bus coding.The analysis of the determinism the fault tolerance and the coding characteristics are given.ARINC 659 supports robust time and space partition and has perfect fault tolerant performance.It is of great benefit for the development and the certification of the integrated modular avionics.